StarTalk Radio - #ICYMI - Playing with Science at BAM, with Sasha Cohen & Neil deGrasse Tyson

Episode Date: April 26, 2018

In case you missed this episode on the Playing with Science channel… We’re taking to the ice as we explore the physics of figure skating with host Chuck Nice, Olympic medalist Sasha Cohen, neuroscientist Dr. Heather Berlin, and resident astrophysicist Neil deGrasse Tyson. Record live at “StarTalk at BAM: Science is Everywhere.” (Adult Language). Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Tanya Cushman Reviewer's Name Reviewer's Name Thank you. Thank you. For those of you who are uninitiated, Playing with Science is a sports science mashup where Neil likes to say where jocks and geeks collide. And I like to say without any concussions by the geeks. Because, you know, when jocks and geeks collide, only one person suffers in that collision.

Yeah, one person walks away. One person walks away, the other one does not. And normally do this. By the way, in high school, I was a geek jock. A geek jock. A geek jock? Yeah. Yes. Yeah, you were a wrestler.

Yeah, yeah. So, but I, intellectually, I associated with the geekiverse. Right. But any time I saw a geek sort of get beaten up or, you know, bullied, that was my sort of superhero, I would, like, the geeks need me. Nice. And I would go and I would like, the geeks need me. And I would go and I would just,

you know. So I felt this urge to protect the geekosphere as a high school kid. What's the superhero name for that? I don't know, but it needs one. I believe it's the Tysonator.

Well, that's very cool, man. So who do you have? But before we get into our guest, who is I believe it's the Tysonator. Well, that's very cool, man. So who do you have? So, but before we get into our guest, who is just so, so, so awesome. Actually, I'm going to use a different word. Who is such a superb guest. He said that because anytime I hear him say awesome, he said it would be awesome if you could pass the salt. I hear him say awesome. He said it would be awesome if you could pass the salt.

And I would say, when I grew up, the word awesome applied to curing polio, walking on the moon. And there's a next generation that has no concept of how to use that word. And I blame the Lego movie. You didn't see it. No, I didn't see the Lego movie. All right.

Everything is awesome! Okay. Okay, let me just say, first of all, I can't tell you how long I've been waiting to do that on stage. But normally this show is co-hosted with Gary O'Reilly, who is a former professional soccer player and the co-host of Playing With Science. And he is currently a broadcaster and he resides in the UK. Unfortunately, his flight was canceled and so he could not be here. It was snowing in the UK. It was snowing

in the UK. No, it was snowing here. And unfortunately, he could not be here. So we, but he is listening right now. Not right now, but he will be listening to this broadcast. So if we could all give a round of applause to Gary O'Reilly. Gary. Gary. And so what we do here is we explore the science of sport. And to help us do that today, we have an incredible guest who is a former Olympic silver medalist.

And she is also, wait, how many times, how many times was it? Oh, God, I I gotta look at these notes because I want to get it right. Five-time world champion medalist, please welcome the incredible Sasha Cohen! I'm so excited to join the fun. It's so great. Thank you.

Hop over here. Have a seat, Sasha. Wait, Chuck, what did she get her medals in? Thank you, Neil. That's okay. The truth is that I took it for granted that everybody would know because you're Sasha Cohen. She is a figure skater. And a damn good one.

And not just a figure skater. You're also an incredible ballerina and gymnast. All of those things rolled in and then strapped skates on and do it all. Exactly. I started in gymnastics. I wanted to take hip-hop. My mom directed me towards ballet for skating. That's because she wanted you to have a job.

Exactly, exactly. What are you talking about? What's wrong with hip-hop? What? Don't worry, your husband is still my favorite white rapper. White science rapper. But go ahead. So that was how I got started. I started in gymnastics because I was basically a bundle of energy and I destroyed the house.

And they're like, how can we calm you down? So I got put into gymnastics for about three hours a day, every day. And when I was five years old, I was doing hundreds of jumping jacks, push-ups, V-ups. And when I got home, I was a very well-behaved child. V-up, is that this here? What's a V-up?

Are you gonna show me? Oh, this, is that a V-up? Do you want me to show you? Yeah. Okay. So you're basically like this, and you're going up like that. Okay, cool. Very cool.

Okay. That's a V-up. That's very impressive, I've got to tell you, right? No, I'm not. Let me see your V-up. You know what? I'm good. You're good.

You're good. You got it. You got it. Later. We'll do that in a little bit. It exists in the space-time continuum. Just leave it there. There you go.

So we, of course, have Heather Berlin here, Dr. Heather Berlin, who is going to break down the neuroscience because there's a lot of neuroscience that goes into pretty much every athlete, correct? Yeah. Like when you talk about the brain and the discipline and the – they call it muscle memory, but it really isn't muscle memory, right? It's actually called procedural memory. So basically when you're first learning, and you'll probably have had this experience, the moves or whatever it may be,

you have to really focus, and you're using parts of your prefrontal cortex. You need conscious focus, even learning to tie a shoelace for the first time. And then over time, over repetition and discipline to do it all those many times, it starts to become implicit or unconscious and it moves into the basal ganglia, which is the sort of subcortical part of the brain

and it becomes this procedural memory or muscle memory. This is what we call muscle memory. Yeah. And it's like riding a bike. And then once you get it into that implicit state, if you become too self-aware of what you're doing, like, oh, exactly how should I hit that tennis ball or do that, it will mess up your flow. So I imagine that you practice it so much that when you go into a routine, you're almost going on autopilot, right? You want to get to that point at which your body knows what it's doing and you don't have to think about it because the thinking messes it up. Because Yogi Berra said that baseball, 90% of the game is half mental. No, it's true. And I think that's where a lot of elite athletes get in trouble and i've

it's happened to me on um you know several occasions is where you train your body do something over and over and over but then you have this one moment and you're like i can't leave it to chance and so you get your mind involved because you also have you know days that you you know you're only practicing an hour a day once you're at competition and then you're just thinking about it over and over and this one moment arrives and it's very hard to put away, you know, the monkey mind because it really wants to be there to help you, but it's like too many cooks in the kitchen. Exactly. And when you turn down that part of the, it's basically the dorsolateral prefrontal cortex that's making you self-aware. Yeah. And that's the inner critic

and oh my God, what should I do? And then if you can manage to turn that down and just enter into the flow state and lose yourself, that's when you really perform at your best. You better watch Heather. She'll tell you to sink it to the ice. So, Neil, you, yesterday, actually, I heard you talking to somebody at another thing we were doing. When you were saying that you skate or you did something at the ice rink where you wore figure skates. What didn't you do? What haven't you done? No, I spent the time in high school as a rink guard. But not with hockey skates.

Not with hockey skates. I wore figure skates. Which is very unusual. Yeah, yeah. Very unusual. The rink guard is like a little more aggressive with hockey skates, but I had figure skates. Yeah, I had on figure skates. Which is very unusual. Yeah, yeah. Very unusual. The ring guard is like more aggressive with hockey skates, but I had figure skates. Yeah, I had on figure skates. Now, I'm just trying to figure this out, and maybe you can tell me.

Because that toe pick can hurt you. That's why you had it. Yeah, yeah. Because you're fierce. You ever see figure skates? There's like teeth in the front of figure skates. And so, yeah. And there were some thugs who came on who were like hockey

thugs. Who knew figure skating was so tough? They were like, you know, beefy, thuggy guys. And rather than fight them, I just challenged them to a race from one end of the ice to the other and everyone parted ways. And they're having hockey skates. So they got to press their feet left and right to go forward. I had a figure skater. I just went up on my toes and just ran. And I got to the end waiting for them to come. So then they shut up after that. So I deeply appreciate your craft.

And as a figure skater myself, as a physicist. We'll have to do the next episode on the rink. We'll race. Oh, yeah. We'll race. Yeah. Oh, that. Fight, take this to the rink.

Meet me outside on the rink with figure skates on in a tutu. Demo fight. Are you aware of the physics that, because they call figure skating physics on ice. There's so much to it. Are you aware of the physics when you're skating, or are you aware of it at all? I think you are aware of it,

but you don't think of it in terms of physics. The way that you define it is this hyper body awareness, and you can feel when you take off for a jump, if you don't have enough speed, if you slightly throw your shoulder too much and you can feel in the air that you're off kilter and that you're going to go down hard. And you also know that if you're doing a single, a double, a triple or a quad, exactly how much torque you have to put in when you leave the ice, because that is what determines how fast you'll rotate and if you'll be able to complete a certain number of rotations up in the air.

So torque is a force that sets something into rotation. And otherwise, it's just a force giving acceleration to an object. So you have force that goes in a straight line, and then you have torque, which is a force turning. So there you are. It's a force you are putting between straight line, and then you have torque, which is a force turning. So there you are. It's a force you are putting between your body, your skate, and the ice so that you can rotate. To launch it, to begin it.

And the same with spinning. And that's something you'll kind of go into a spin slow, and then you'll glide in, and you'll ride the edge, and then you'll take the right side of your body, and you'll snap it to begin the spin. And then you'll use your arms and legs to increase your speed or slow it down. Oh, my God. All right.

I'm learning how to physics skate. Physics skate. Physics skate. I'm learning how to physics skate. You just invented that word. I did. Physics skate. Physics skate.

So here's what I would love to physics skate. I learned how to physics skate. You just invent that word. I did. Physics skate. Physics skate. So here's what I would love to do. For those of you who are listening and do not have the benefit of visual because everybody is here, if you could stand up and just show us the actual, but you have to talk it through because people are listening at home. If you could show us the physicality of what happens when you're doing that motion and then Neil, if you can break down exactly what's happening from a physical standpoint, I think that would be really cool.

I'm making this up as I go along. Wait, wait, so Chuck, no we do this. So we can pretend like we're the Olympic announcer. Sasha Cohen. And this is what she's doing. This is what she's doing. So Sasha Cohen, she's wearing high heels at this moment. I am wearing high heels, but I've not done it this way before.

So what happens? So there's two instances, right? There's a jump and a spin. And I feel like everyone, if anyone's watched any figure skating, is somewhat aware of the difference. One, you leave the ice, and one, you don't. The jump, you leave the ice. So. Chuck, you got that?

Yeah. You know what? I'm keeping up. You're with it. We'll start with the jump. Okay, stay with this, Chuck. So, for instance, I will start with a sow cow. And so it's something where you're going to take off backwards,

and you're going to be gliding on the inside edge of your left foot, and you're going to determine how much speed you want to get going in, right? So I'll be doing crossovers and running and running and going fast. Building your speed. Right. And then people have different entrances. But say, like, when I, many, many, many years ago, I did a quad salchow and I wanted to get extra torque.

So I would do a turn ahead and then I would set myself here and then I would use the edge gliding backwards, the right side of my body, and I would dig in with my left foot into the ice and whip this up. And that's what would initiate the momentum. And I would leave the ice, push off this topic, and then immediately snap the weight over my right side. And based on how much I followed through with my right arm and right leg and pushed down with my left

would determine how fast I would spin and if it would be a single jump, a double jump, a triple jump, or a quad. Wait, can I ask you a question then? The way you just broke it down was a very logical, conscious, whatever. But when you're actually doing that, you're not thinking all those things, are you?

Are you feeling them? You feel it. You feel it. So I think I'm explaining exactly what I feel. Right. But it's like you're very fine-tuned and you know exactly how much speed you need. And you know how much speed is too much that you'll lose control. That it could turn out great, but you have to get lucky.

Because basically speed magnifies anything. It helps you get more height and more torque. But if you are one millimeter off in any direction and you have extra speed, you're going to go down really hard or your alignment won't be quite right. So people are a little tentative with speed because that can, you know, you can go up in flames. It's like putting leverage on your house. It can work out really well or it just can go bust. But now, finally, something I can relate to.

No leverage. Wait, wait, wait. So, Sasha, if you, you, so, so, I get, you gave a brilliant description of how you give yourself rotational inertia. Okay? For a jump. We haven't even gotten to the spin. But, however, you didn't, well, okay, to me, in physics,

you generally break things apart into components, and you put them all together for the one thing. I break this apart. You told me how you gain spin, but if you're going to do a quad, you have to be airborne long enough to complete the quad before you hit the ground. Yes. That's part of it because you'll notice, if you've watched figure skating this past Olympics, you will see some people barely get off the ice

and they can do three turns, and some people get this high up and they don't complete it. Two or three feet off the ice. So it really is the rotational spin. It's how fast you launch yourself up. Gotcha. And then obviously it goes into what's your body type, do you have wide hips, how fast you launch yourself up. Gotcha. And then obviously it goes into like what's your body type? Do you have like wide hips?

How fast are you spinning? And that's why men rotate faster and generally do a lot more quads than women do. They spin faster. They've got narrower hips. But, you know, women are more flexible, so we've got better spiral sequences. How many women have done quads? You know, a couple have done it in practice, and I feel like maybe like one or two have done it in competition. And you've done quads? You know, a couple have done it in practice, and I feel like maybe one or two have done it in competition.

And you've done a quad? I have. A long time ago. A long time ago. Thankfully, YouTube exists, and it will always live there. I hope. I'll be like, wow, I used to do that. Now I just sit.

I just sit. So people must have freaked out. I mean, did the announcer lose his shit? I mean, it was an exciting moment because, you know, people can see when you get really close or you're double-footed or you step out. But when you actually do it and you're kind of, you come down from four turns, and you have to have tremendous amount of strength and balance

to catch yourself when you come down, get out. And so it's this moment where it's like, oh, is she going to do it? Is she going to do it? And you have it, and it's very exciting. It was exciting. It was. So there's the launch and the landing that both matter. Yeah, so when I trained, you know, you'd work on explosive muscles for bounce.

And then you would also, I would jump down off of boxes this high in order to kind of learn how to absorb all that pressure and momentum coming down. And you do that with the skates on? Off-ice training, I do it without skates. And then on the ice with skates. Well Off-ice training, I do it without skates. And then on the ice, with the skates. Well, that would make sense. Thanks, Sasha. No problem, no problem.

Just want to keep it clear. You asked. No misunderstandings. But then let me get to a spin, because a spin is very different, because you're not launching yourself out. And it's something that goes for much longer. It's not fractions of a second. A spin a spin, you know, can be 30 seconds. It can be a minute. And you basically, you'll see most people wind backwards and they're creating this. It's all

about torque in the body. And this is why I realized I'm a terrible skier because it's the opposite. So they're winding the spring. You're winding, right? And so my hips are going to the left and my shoulders are going to the right. A lot of abs, a lot of abs. Core work. Yes. And then, and then, so then you step in and you ride this outside edge. And then again, you do the same whip momentum for a jump, except you don't take off. And then you, you spin. Generally, if I wasn't in heels I could do more spins. And then once you're there you can you'll keep this momentum and then as I would bring in my arms and my legs I can just insanely increase the speed of my spin. And likewise if all of a sudden I wanted to slow it down I would just open

up and you would see the rotations just kind of almost stop. And so in that way, I was aware of physics. But for figure skaters, we would think about it more in terms of like body awareness of where your hips are, what torque you need. Plus you have to look good doing it. Yes. Right, because you're being judged. And what color you look good in. Right, right.

There are other dimensions of the analysis, of the rank of the scores. Exactly. Right, right. There are other dimensions of the analysis, of the scores. Exactly. Right, right. So you actually, yes, can you tell us what is happening when she does that? Oh, the physics, yeah. Yeah, so if you, let me take my shoes off. I want to see you say it. Oh, stop the saying. Wait a minute.

For those of you listening, Neil is taking off his shoes and putting on Saucer's heels. Cinderella doesn't fit. Doesn't fit. All I can tell you is this. Prince Charming is never coming back. Thank you. So in physics, here's the deal. So if you set yourself rotating, all right?

So I'll do that right now, okay? So here I am rotating, okay? So that's at a speed. Wait, don't applaud yet. You don't know what's about to come, okay? So, so. So you just spun around. So you can calculate how much angular.

So in physics, you might remember from your physics class if you had it. So everything that happens in a straight line, you can think of in a rotation. So there's a force. The rotational counterpart is torque. There is mass. The rotational counterpart is torque. There is mass. The rotational counterpart is moment of inertia. There is, you also have momentum. And the rotational counterpart is just angular momentum.

So here's the thing. Once you start rotating, your angular momentum is constant. Okay? It's constant. Okay. It's constant. So if I start spinning and you calculate the angle momentum by, okay, here it is. It is the mass of whatever your body is, which in this case would biggest figure skater ever. Here's the point. So your hands have a certain mass. Okay.

And they're rotating out at this distance. So you have part of your body mass away from your axis of rotation. Oh. Okay, so you can calculate how much angular momentum that is, now watch. If I bring any part of my body closer to my axis of rotation, then one of the terms in your angular momentum drops.

So what happens is the distance to the axis of rotation drops, but your angular momentum stays the same, so something has to increase. So, ah. Okay? So, because when you multiply these two numbers, you have to get the same answer every time, okay?

So if I start changing the distance of the mass of my body to my axis, and I make it smaller, I have to spin up. Nice. Nice. And so there you have, allow me? Yes. Yes, may I? Okay.

So I will spin and then. Okay. And just like she said, because what she needs, right? Right, isn't that right? So you're spinning, you speed up, but then you can stop it by just putting your mask back out. So here's my proposal to you.

Okay? Here we go. Okay. So I don't know if this is legal. Okay. Hashtag me too. Here. So put your arms out.

Okay? So you're my skating physics demo in this moment. So you have a certain amount of mass coming out here, all right? So wait, for those listening, right now, Sasha has her arms spread apart. Spread apart, yes. And in a T formation, and go ahead. Exactly.

So there's a certain amount of mass along your arm and in your hands. And you also showed earlier, when you start a spin, you might start with your leg out, okay? And then when you bring your leg closer in towards your axis of rotation, you start spinning faster. And okay, so we got this. Oh, I like you have an, this is an infinity on your wrist. Very cool.

Very cool. It's an infinity tattoo. Yes, that is an infinity tattoo. It's an infinity tattoo, good. Okay. Sorry, I is an infinity tattoo. It's a huge. Okay. Sorry, I didn't mean it. Okay, so here's my suggestion. I don't know if it's legal.

Next time you do this, I think you can do a quint. Is there such a word? There is such a word. Good, quint, five turns. Now how would you do that? I'm gonna say you get some lead weight to put in your hand. It's Tom Brady all over again. Tom Brady of ice skating.

So when you start, when you start spinning with lead weights in your hand, even if you're spinning at the same speed that you once were, you have more mass farther away from your rotation axis. So that as you then bring the more mass in, you will spin faster. And I don't know, people will notice if you're grabbing something, holding on to something. Oh yeah, what's going on?

So maybe you, as you skate around, as you skate around the ring with two kettle bells in your hand. It's a little obvious. So what you do is... Just get really heavy rings. Really heavy rings. You can get a wrist bracelet and lead infuse the wrist bracelet and you're just, it's just your jewelry.

Meanwhile I build up huge arms. So what I'm saying is, if you did that, the same gestures, you will spin faster. And you'll have to land, you'll have to figure out the landing. But once you go... I'm going to throw this back to you. What's that? For spinning, this would absolutely work, and it would give me more torque and momentum when I spin. Yes.

But I think the extra weight would not allow me to get up as high in the air. And so even if I got extra torque when I pulled in, I would still not be able to rotate as many times. You need to work on this. So to trade off, you have to think about that. It's a good thing to think about. You got to think about that. So this is one of the interesting physics problems where there are two variables competing with one another, and you don't know if one is more powerful than the other or where they meet to get the best combination of both.

And that's where you get more interesting complex problems in physics and in life. I have a neuroscience problem here that I can address. You know, why don't you get dizzy when doing all these things? Oh, yeah! So I have an explanation for that. You know, why don't you get dizzy when doing all these things? Oh, yeah. What's up with that?

So I have an explanation for that. You know Chuck and me. If we did that, we'd be like. Are you kidding me? Because they're going around and around and around. I'm dizzy right now. So, you know, there's actually a neuroscientific explanation for that question. So it's interesting.

For jumping, you know, it happens in a fraction of a second, and you don't get dizzy. It's just very quick. But spinning is something where ballet and skating really diverge. You know, if you're a ballerina, you're spotting, you know, like to the edge of the room and that's how you're keeping, you know, your awareness. And by spotting, you mean you pick a spot, you turn your head very quickly back to that spot. And you like, you turn. That prevents you from getting dizzy? For ballet. For ballet. This is what ballerinas do.

They always spot. But for figure skaters, you're spinning so fast, and you're not doing just like kind of one, one, one. You're literally doing, I don't know, like 50 turns. And the trick is you have to stay in the same center, so about like one to two blade lengths. And I don't know. I think it's like something to stay in the same center, so about one to two blade lengths. And I don't know, I think it's something to do with your inner ear, that if you're not traveling and you're staying in the same spot even though you're spinning,

you don't get dizzy. But from personal experience, when you do a spin and you do a bad spin, which you get a deduction for, and you're traveling, so you kind of start here and I end up off stage, you get out of the spin and it's like a cartoon where you see the stars and you're just like, what, where am I? And so that's why they teach you have your center and don't travel. So explain that inner ear to me in like neuroscience terms. So your inner ear consists of these three like fluid filled tubes,

right? And each one is at a different orientation, so it's meant to be sensitive to a different orientation. Let's say if your head goes up like this or no or side to side. And within those fluid... So these are the three dimensions of space. Yeah, the three dimensions. And they're represented within your inner ear in these little tubes. And within each of these fluid-filled tubes

are these little hairs that are like sensing. It's almost like seaweed at the bottom of the ocean. So when you move, it senses and sends signals to your brain. So if you think about if you're in a chair, let's say spinning and you're holding a bottle of water and you're spinning in this swivel chair, and then you stop, the water is going to keep going, right? Because it builds up momentum. And the same thing is happening in your inner ear. So it's telling your brain you're still moving. That's why people get dizzy. And also there's messages. Well, that's why when you stop spinning, you fall over because you can't keep your balance because your brain didn't figure out that you stopped spinning.

It thinks you're still moving. But then there's also information. So there's information coming to your brain. But your muscles are telling you stuff as well. There's proprioceptive input and there's also visual input, right? Giving you information. What kind of input was the muscle input? Proprioceptive. Proprioceptive. Like proprioception. Yeah. Proprioceptive. Oh, that cleared it up. I've heard that one before. Yeah, it's proprioceptive. Like proprioception. We good now?

Yeah, we good. We good. We're going to move on. You're opening us up. It's signals that tell your body it's awareness in space. So your brain is getting that information from your muscles and your joints. The inner ear is telling you you're still moving. And your eyes are giving you information. So that's why they often say, and tell me if they say this to you, when you're at it, when you come out of the spin, different than ballerinas, you

focus each time they make a turn, but you then are told to focus at a specific point because you want to have your eyes telling your brain counteracting what your inner ear is telling it, that it's still moving, that you're not moving any longer. And also what you do, I'm sure, is you practice off ice, just spinning so that your brain can habituate. So it's not so much that you're spinning in one place versus moving, although the movement is going to cause it to be more confusing because there's moving in different directions. So it'll be less of a movement if you're in one space. But that's not what I think is happening. I think you habituate because you practice, right? So your brain just becomes acclimated to spin. Yeah. It's only so much though, right? Because it's still a physiologic effect, right?

And what you'll see figure skaters do is they'll spin very fast and then they'll slow down. And they slow down, they're kind of getting their bearings. And they're readjusting their brain. So you're kind of easing yourself out of it. Exactly. And then there's like a trick move that you do is you spin really, really, really fast and then you stop.

And then you give yourself, you do it to the music. It's like, ba-bam. And then you give yourself like you do it to the music. It's like, ba-bam. And then you give yourself like a second, and then you're like, ah. Give me my arm now. You just like, you have a little choreography like you built in. You know, we have these like these breathers

and so on after a spin. But Sasha, is it true that your fastest spin in any performance is the spin you end on? So you don't have to be graceful and balancey after that. It's true. People generally do their more strenuous, like wham, bam, hit every position. It's like very dramatic at the very end. Also because it takes up a lot of energy and you want to get your jumping passes in earlier. Although you're seeing that change now a lot with the new judging system where you're getting rewarded and getting more points if you jump after the halfway

mark but generally you want to end on a big note and so people will do combination spins where you hit like six different positions you're in a camel you're in a sit spin you're gonna lay back and then you're on the other foot and your legs up so there's a lot going on. It's like a fireworks finale. It's a fireworks finale. It's just like, put them all up there. That's one a fireworks finale. It is, exactly. It's a finale. It's a fireworks finale. You got it. It's just like, oh, put them all up there. Come on. That's one.

That one. Oh, yeah. Look at the smiling face. Oh. Everything you got. Throw it at the end. So, Heather, let me ask you this, because we are almost out of time. Why is it that, from a neurological standpoint, that that is our first kind of foray into getting high?

You see children spin around, spin around, and then they're just like, oh, I am messed up, man. Like, what is happening there? Well, a lot of what drugs do is they kind of play with your senses, right? So normally we have input coming in from our senses, and our brain is organizing in a certain way. But when you kind of mess with your senses and the way the brain is interpreting them, that's also what drugs tend to do.

And it's interesting because it's a different brain state. And it's not just your inner ear, by the way. Those inner ear, that information goes to that little brain in the back of your brain, the cerebellum, right? It's right in the back of your neck. And what's interesting is that that has two times as many neurons as your entire brain. Oh. Right?

Whoa. Two times as many neurons. Twice. Yeah, twice. It's two. Two. Twice. Two times as many neurons.

But it's unconscious, okay? And people who have complete damage to the cerebellum, they are still fully conscious. I mean, they might have less coordination. They can't do triple axles and things, but they're fully conscious and aware. So we only need basically one third of our neurons to have conscious awareness. But it's interesting how much goes into that ability

to have balance. But I think the reason why it feels good is that we like different sensations. We like to be outside of our normal, even dream states or creative states or daydreaming. When we're not in that normal state where the prefrontal cortex is on and everything's working properly, it's fun. It's interesting. That's why we like to go on roller coasters or rides that make us feel weird. So Sasha, when you're performing, you're in an altered mental state, according to this. Maybe that's why I became a figure skater.

It's like the world is going to be too much. I need to skate for 20 years. That's why you drink before competitions. That was our secret. So Chuck, I have one kind of hyper-geeky thing left to say about figure skating. Go ahead. Do we have time for it?

Sure, go ahead. You sure? Go ahead. Okay. But it's kind of, it's like embarrassingly geeky. Are you sure? You know, you could tell me private. Okay. So, so here it is. And it'll take a few minutes, but it's just, okay. Most things, when they get cooler, they will shrink. Boy, do I know it. Water. Water. Water. Water, water does the opposite. Okay? If you cool water, take its temperature down to 32 degrees, it freezes and gets bigger.

The same amount of water occupies higher volume after it freezes. And so the water, the frozen water, the solid water is less dense than the water from which it came. floats. Okay. This is profound. Because you can have a lake with fishes in it. Winter comes. Winter was coming. Winter comes. I like that show.

Okay. Did you see my dragon tweet with the dragon breath? I did not see your dragon tweet. Forget you, Dan. All right. So a lake, so it gets cold outside. Temperature drops below freezing.

The water at the top feels this temperature, okay? So what happens? It turns out as the water does get smaller, but then it gets bigger again. And at four degrees Celsius, water is at its densest. So the air is cooling the water. It hits four degrees. It drops to the bottom of the lake.

And then it cools another, drops to the bottom, drops to the bottom. Finally, the cold air catches up with the water and the water, it freezes the water and it creates a lid of ice. Now, the temperature stays cold. How is it going to get to the water below? It can't.

And that ice insulates the lake and does not kill the fish. Nice. If the ice were denser, this all relates to figure skating. That's why I said it's geeky. I told you. Wait till you get the skates on these fins. So if ice sank, then systematically the cold air would freeze the lake from the bottom up.

And the fishes would have less and less and less water to swim in. And that last layer would freeze and you would kill every single fish every single winter. But we have frozen lids over running streams in every municipality everywhere. Okay. So now. This really is geeky. You're right. I told you. Okay. So now. This really is geeky. You're right. I told you.

Wait. So now, suppose I have a block of ice and I want to squeeze it into a smaller volume. You can't. I know. As long as it stays ice. Okay, so now what? Oh, that's awesome, man. I told you. Yes, you're right.

Told you. Oh, my God, this is so geeky, it's great. But it's still coming. Sit down. Okay, okay. So now, the geek is building. Oh, my God. So.

Just let me give a quick aside. Pipes. Pipes have water flowing in and it's cold outside. Okay, watch. And it's cold outside. I blame myself. The pipes are holding on to the water. The water is trying to get colder and it gets colder and colder and colder. It gets to 32 degrees and it wants to freeze,

but it can't because the pipe is holding it. But the temperature gets even colder and it wants to freeze even more, but it can't because the pipe is holding it. The ice, the water will go to 32 to 31 to 30 and it won't freeze until it wants to freeze so badly it becomes ice and pops your

pipes. No matter what they're made of, it'll pop your pipes. Oh, now that sounds good. Becoming, becoming ice. Now watch. That's what I'm talking about. So now watch. Okay, so. If you reverse that, if you squeeze ice,

you will melt it. If you squeeze it hard enough. Pressure. Pressure, pressure. Pressure. So now watch. Come on, baby, pop my pipes. Sasha glides on the ice,

not because ice is slippery, but because her skates are sharpened, not like a knife edge, but if you ever see a cross section of an ice skate blade, it's actually concave. It's concave. So you have two edge. You were speaking about which edge you're on. So if you're skating on an edge, her weight, even though she don't weigh much, that weight is sitting on top of a tiny area of metal blade. And pressure is force per unit area. And if the area is small,

the same force over that area becomes a higher pressure. That's how the math works out. So what's actually happening when she skates is that the ice beneath her skate blade melts the instant her blade touches it. And she's gliding on a bead of water on top of the ice. That is what she's doing. She's compressing the ice. It melts instantly because the ice can't stay ice. In a smaller volume, it becomes water immediately.

I got to be water. Okay, so watch. So she glides over it, the water, the ice melts, so she's smooth. And the moment the blade comes out the other side, the water refreezes instantly. So you think it's because the ice is slippery. No, it's because the water is slippery. Now, there is a temperature below which even the high pressure cannot melt the ice. There was an expedition to the South Pole in 1911, the Scott Expedition. He had a team.

He had sleds with skate blades on it, okay? Gliding over the ice. He got to the South Pole too late because the admiral, what's the guy? Admiral whatever. He got to, he wasn't, he beat him to it. Okay, fine, so he's ready to go back. Antarctica went into a deeper freeze than usual.

They were, the moving was slow. They were running out of supplies. They had to get to a supply station. They got within 11 miles of the supply station and they couldn't go any further. You know why? Because they were moving so slow and it was taking so much energy. They had to eat their dogs, okay?

They ate their dogs, and that was not enough. And now they got nothing to pull the sled. So the humans are pulling the sled, and they're pulling, and there's a point where they can't pull the sled anymore because the temperature dropped so low, the sled blades were no longer melting the ice on which they glided and their blades just froze

in the ice. He could not make it to the 11 miles to the station and everyone on that expedition died. And this is the story that Neil used to tell his children every night. Why didn't they walk? Why didn't they just walk and leave that Neil used to tell his children every night. Okay.

Why didn't they walk? Huh? Why didn't they just walk and leave the sled? They were all men, obviously, and they didn't think of that. They had actually, we got to wrap of that. They had actually collected rock specimens that they wanted to bring back to England with them, and those rock specimens were just sort of dead in place with the rest of them. Later on, we came back, found the rock specimens,

and they contained fossils of ferns and other prehistoric life. Evidence that Antarctica was not always ice. This was a scientific expedition and they gave their lives for science. Yes. Chuck, we gotta wrap it. I'm gonna tell you the beauty of that story. Not one of them was black.

You will not find a frozen black person anywhere on this planet. That is it for playing with science. Please give it up for Dr. Heather Berlin. Olympic medalist, Sasha Cohen. The inimitable Dr. Neil deGrasse Tyson. I've been your host for Playing With Science. Also, please give it up for Gary O'Reilly, who is not here.

And our catchphrase is this. If you play with fire, you get burned. Play with science, you get learned. Chuck you in the house. Woo! Bam! Get home safely. Have a good night.